Stoker



' March. 31, 1942.

F. W. VODOZ STOKER Filed April 14, 1959 6 Sheets-Sheet 2 MC d TTORNE Y5.

March 31, 1942. w, voboz STOKER Filed April 14, 1939 6 Sheets-Sheet 4 11v VENTOR 7719470163 /44//d4 0z.

9M. A TTORIVEYfi March 31, 1942. F. w. VODOZ STOKER Filed April 14, 1939 6 Sheets-Sheet 5 I 5 lllllllixlillll\lllllllllllliilllJ ATTORNEYS.

l I I I I l I I A 4 I I I I I I I I I I l l l l I lll nnrlnfilllrublll'k Patented Mar. 31, 1942 STOKER Frederick W. Vodoz, Wilmette, Ill., assignor to The Murray Corporation of America, Detroit,

Mich., a corporation of Delaware Application April 14, 1939, Serial No. 267,841

12v Claims.

' My invention relates to stokers, and'particularly to a stoker-of the over-feed self controlled type forming a complete unit which is movable to and from a furnace.

The present invention is an improvement over the stoker illustrated and described in my United States Patent No. 2,075,149, issued March 30, 1937. In the patent, a stoker is illustrated, described, and claimed embodying a unit having a hopper below which a shovel and ejector are disposed and operated in a predetermined manner. A motor is mounted on the stoker for advancing the shovel'and ejector after which the ejector advances relative to the shovel to dispose a predetermined amount of fuel centrally of the fire box of the furnace. An arm is provided forwardly of the stoker projecting within the furnace to rest upon the fuel deposited therein and to be retained in raised position by the fuel. As the fuel burns, it settles within the fire box carrying the arm downwardly therewith, which,

after being lowered a predetermined amount, actuates a switch to energize the motor to produce another injection of the fuel into the fire box.

The stoker herein illustrated and described, while embodying the principles as outlined above and to be found in the mentioned patent, contains improved structure which simplifies the operation, the adjustment, and control, and seals the hopper, shovel, and ejector relative to each other to prevent the accumulation of particles of fuel in the mechanism and the scattering of such particles over the floor.

The operating mechanism is so constructed that the degree of movement between the shovel and ejector and the extent of movement of the ejector is adjustable and, readily accomplished without requiring the shortening of the driving against the sliding surface of the shovel and ejector to effectively seal such surface during movement while a downwardly projecting flange on the hopper seals the top of the shovel and prevents fuel particles from passing over its top.

ported on the front end of the stoker to take the chain. A flange of sealing elements is forced place of the furnace door. The plate is adjustable'to be disposed at various angles to conform to'the angle of the marginal edge of the wall of the fire box opening.

Accordingly, the main objects of my invention are; to provide a drive mechanism for a stoker which moves a shovel and ejector a predetermined distance relative to each other; to provide adjustable means whereby the stroke of the shovel and ejector may be altered when moved together and also altered when moved relative to each other; to provide a continuous chain on a pair of sprockets which operate an arm that engages an adjustable abutment to provide for a free initial movement of the arm to thereby regulate the stroke of the ejector; to interconnect the shovel and ejector with a latch which'regulates the degree of movement thereof together until disconnected by an adjustable element which thereby regulates the amount of travel of the shovel; to provide an element secured to an extension of the hopper which seals the extension with the top of the shovel; to provide flanges over the top edges ofthe shovel to prevent leakage of fuel between the shovel and its enclosure; to provide a door on the end of the shovel which automatically closes and opens as the shovel is retracted and advanced.

Other objects of my invention are; to provide an angle shaped plate on the bottom of the door which forms a box section enclosure to prevent heating of the top face when the door is disposed in advanced position in the fire box; to provide a pushing edge on the shovel door which scatters the burning embers and provides a flat surface for the reception of the additional fuel; to provide a closure plate on the nose of the stoker to seal the nose with the edge of the furnace opening after the door'has been removed therefrom; and in general, to provide an improved structure for an over-feed stoker which materially increases the efficiency of operation thereof and which is economical of manufacture.

Other objects and features of novelty of my invention will be either specifically pointed out or will become apparent when referring, for a better understanding of my invention, to the stoker illustrated in Fig. 1, taken on the line 3-3 thereof;

Fig. 4 is a sectional View of the stoker illustrated in Fig. 3, taken on the line 44 thereof;

Fig. 5 is a sectional view of the stoker illustrated in Fig. 3, taken on the line 5-5 thereof;

Fig. 6 is an enlarged sectional View of the stoker illustrated in Fig. 5, taken on the line 66 thereof;

Fig. 7 is a sectional view in perspective of the under side of the ejector, illustrating the operating parts providing the adjustment therefor;

Fig. 8 is a view of structure similar to that illustrated in Fig. 3, with theshovel and ejector in advance position;

Fig. 9 is an enlarged front view of the furnace end of the stoker as viewed from line 9--9 of Fig. 3;

Fig. 10 is an enlarged sectional stoker illustrated in Fig. 3, taken I -I 0 thereof;

Fig. 11 is an enlarged sectional stoker illustrated in Fig. 3, taken ll-H thereof;

Fig. 12 is an enlarged sectional stoker illustrated in Fig. 3, taken l2-I2 thereof;

Fig. 13 is a sectional view of the plate for sealing the stoker to the furnace opening; and,

Fig. 14 is an exploded view of the end of the ejector and the sealing element associated therewith.

Referring to Figs. 1 and 2, a stoker of the over-feed type is illustrated, embodying a base view of the on the line view of the on the line view of'the on the line 14, adjustable standards l thereon carrying a housing IS on which a hopper I1 is supported. The base 14 is provided with rollers l8 and a coaster lSa by which the stoker is moved to and from operating position with a furnace I 9. A control arm 2| is mounted on the front end of the housing [5 connected to a switch 22 which is closed by the arm 2| when in lowered position to energize a motor 23. The motor drives a shovel 25, which projects from a nose 24 attached to the housing l6 to produce an injection of fuel, such as coal, coke, and the like, into the furnace fire box.

A foot 26 is provided on the base, operated by suitable links from a lever 21 to raise one end of the base from the floor to thereby lock the stoker in position relative to the furnace. Other links interconnect the lever 21 with the arm 2| which is moved to raised position when the foot 25 is raised to lower the base on the wheels. The arm 2| then extends in substantially a horizontal position so that the stoker may be moved to and from the furnace without coming in contact with the parts thereof.

The housing I6 is provided with a base stamping 28 as illustrated more clearly in Fig. 5, having an embossed portion 29 on which is riveted an arcuate plate 3| with which rollers 32 of a link chain 33 contact. An embossed portion 34 is provided along the one side having apertures 35 therein in which a stop element 36 is secured selectively in one or another of the apertures 35. Downwardly presented U-shaped straps 31 having flanges 38 thereon welded or otherwise secured to the base plate provide support for the shovel 25. An aperture 39 is provided in the plate having the edge thereof flanged downwardly at 4|, as illustrated in Fig. 3, whereby any fuel particles or dust may fall through into a pan 42 which is slidably supported on flanges 43 projecting inwardly of the flange 4 I, as illustrated in Fi 10.

The motor 23 is supported on the underside of the base stamping 28 by the bracket 44. A speed reduction unit 45 is also secured to the under side of the base stamping 28 having its shaft 46 projected therethrough and connected in driving relation to the shaft 4! of the motor by the coupling 48. The speed reduction unit 45 has a sprocket 49 mounted on its shaft 5| in the plane of the arcuately disposed plate 3|. The chain 33 is disposed over the teeth of the sprocket 49 .and is driven thereby.

The nose 24 embodies a stamping 52 of channel formation having embossed portions 53 which also form a support for the front end of the shovel 25. An inwardly presented channel 54 is formed in the nose 24 along the lower lefthand side wall, as viewed in Fig. 10, to provide clearance for the switch tripping cam 55 carried on the outer surface of the wall of the shovel. The nose 52 is secured to the housing [5 and is covered by a plate 56 projecting from the front of the hopper, having downwardly projecting flanges 51 which are welded or otherwise secured to the ends of the side portions of the nose 52. Two shields 58 are secured to the inner top face of the sides of the nose 52 and between the outer wall of the hopper l1 and flanges 62 of the housing IE to have the downwardly projecting flange thereof extend inwardly of and over the top edges of the shovel 25.

The housing I6 embodies side plates 6| which are secured to the rear portion of the nose 52 and to the under side of the base stamping 28- and supports the hopper IT on outwardly directed flanges 62 thereof by the bolts 63.

The standards l5 are welded to the side plates 5| of the housing I-B, as illustrated in Fig. 12. A cover plate 60 joins the two projecting sides of the plate 6| to enclose the top rear portion of the housing while a removable arcuate shaped cover 50 encloses the rear portion. The shovel 25 is of channel cross section at the front half portion thereof, the rear half portion being cut out to provide inwardly projecting supporting flanges 64, as illustrated in Fig. 12. This provides an opening in which the actuating mechanism may operate to move the ejector 65, the rear end of which is provided with brackets I00 which rest upon the flanges 54 at the sides of the shovel to provide support for the rear end of the ejector. The sides of the shovel extend forwardly at the front end at 66, providing an opening therebetween enclosed by a door 51 hinged on a pivot. An arm 69 extends downwardly below the pivot engageable with the flange H on the nose 24 by which the door is actuated to closed position when the shovel is retracted within the housing IS.

The door 61 has on its underside a stamping l2 welded or otherwise secured thereto to form a box section structure which prevents the top face of the door from heating an excessive amount when disposed within the fire box in the furnace. The front edge 13 of the door functions, during the inward movement of the shovel, to scatter the burning embers, fuel and ash to provide a surface on which the fuel may be injected. The shovel, above the flanges 64, has welded to the sides thereof a platform 14 provided with a downwardly deflected forward lip 15 which rests upon the top of the ejector 65 to provide a sliding seal therewith.

The hopper is provided with an extending portion 16 having sides 11 which overlap the sides 18 of the platform portion 14. The end of the extending portion16 is-fianged downwardly at 19 into a channel elementBI for forcing a lip 82 thereof against the surface of the platform portion 14 to form a seal therewith. Below the platform a latch 83 is mounted on a pivot 84 secured to the side of the shovel. The latch has an engaging end 85 which projects into a slot 86 of the ejector 65. A detent is also provided on the latch which engages the adjustable stopblock 36 to move the engaging portion 85 of the latch from the aperture 86 in the ejector to prevent the further movement of the shovel as the ejector continues to advance.

The ejector has a downwardly extending flange 88, as illustrated in Fig. 14, at its front end, which is arcuately shaped to rest in the channel of the spring element 8| to rock therein and force the forwardly extending lip 82 thereof against the surface of the fioor of the shovel to form a seal therewith.

On the underside of the ejector 65 a channel shaped element is secured, having a flange 9| near one edge in which a plurality of apertures 92 are disposed. The element 9| is flanged outwardly at 93 to provide a slot with the underside of the ejector surface. The remaining flange 94 of the channel shaped-element is disposednear the other edge of the ejector and is provided with slots 95 forming projections therebetween having apertures 96 therein. The web between the flanges 9| and 94 is provided with a central slot, the material 93 either side thereof being spaced from the ejector.- A cross bar 91 has a projection 98 on one end which extends through the aperture92 while an aperture 99 near its opposite end receives one of the projections between'the slots 95. A cotter pin |I locks-the cross bar 91 on to the projection. The cross bar 91 is adjustable in different positions along the underside of the ejector by selecting the proper aperture and projection towhich it is secured, to therebyproduce the desired degree of movement to the ejector.

A pivot I02 on a link I83 has its head I82a enlarged and disposed within the slot 'I I6 provided by the flanges 93.0f the angle elements SI and 94, for sliding movement therein. The opposite end of the link I03 is provided with a pin I04 secured to the link chain 33. The portion of the ejector 65 rearwardly of the aperture 86, is deflected downwardly at I05 to engage the detent 81 on the latch 83 to move the latch in a clockwise direction to project the engaging end 85 thereof within the aperture 86.

When the chain 33 is actuated, thepin I04 moves therewith and moves the arm I03 so that the pivot I02 advances in the slot I|6 until the arm abuts against the cross bar 91, after which the ejector moves forwardly therewith. In view of the projection of the engaging end 85 of the latch 83 in the aperture 86 of the ejector, the shovel is carried forwardly along therewith. The combined movement of the shovel and ejector continues until the detent 80 engages'the stop block 36 to swing the latch 83 in counter-clockwise direction to have the engaging end 85 thereof move out of the aperture 86 and the forward movement of the shovel is thereby terminated. The continued operation of the chain continues the forward movement of the ejector 65 until it completes its forward movement. As the pin I04 advances about the sprocket 40, the arm swings about the pivot I02 which -moves rearwardly away from the cross bar 91 to the rear end of the slot H6, whereupon-the ejector is moved rearwardly along therewith. The shovel 25 is prevented from moving rearwardly therewith by the detent90 on the latch 83 engagingthe stop block 36. As the projecting end portion I05 of the ejector engages the detent 81, the latch 83 is rotated clockwise to release the detent 90 from the stop block 36 and the shovel is carried rearwardly therewith untilthe pivot I02 reaches its maximum return movement. The driving mechanism is free to repeat the movement of the ejector and shovel as controlled by the switch 22.

As pointed out in the above mentioned patent, and as indicated hereinabove, the arm 2| is interconnected by alink I I5 which carries the mercury switch 22 that connects and disconnects an electric circuit to the motor 23. The cam element on the side of the shovel 25, near the end of the movement of the pin I04 to its initial position; engages a cam I06 which operates the switch 22 to its initial or open position to disconnect the electric circuit to the motor. As the fuel burns in the fire box of the furnace, the arm 2| drops until it reaches such a position as to operate the link II5 to move the switch 22 away from the cam element 55 which is moved to closed position by a-spring to again produce a cycle of operation to the stoker.

The nose 24 of the stoker is closed by a door I01 carried by a pivot I08 upon which'the arms I09 of the control arm 2| are pivoted. When the shovel 25 is moved forwardly through the nose 24, the door I01 is moved to open position, raising the control arm 2| therewith as illustrated in Fig. 8. When the shovel is returned to its initial position, the door automatically closes and the arm 2| remains in raised position on the fuel which has been disposed on the bed within the fire box. A baffle I I I is secured on the underside of the plate 56' which forms the'nose 24, to regulate the flow of fuel from the hopper I1 into the shovel. The nosealso carries a plate H2 having brackets |I3 thereon in which bolts are threaded, the ends of which project into one of a plurality of spaced apertures M4 to support the plate at a predetermined variable distance from the end of the nose for tilting movement. The end of the nose is positioned relative to the fire box of the furnace, while the-plate may assume an angle conforming to that of the slope of the furnace opening,

After a fire has been kindled in the furnace, the stoker may be moved into position to have the plate II2 close the opening thereof with the control arm 2| resting upon the fuel. As the fuel burns, the arm lowers until suchtime as it operates the switch 22 to closed position to complete the circuit to the motor. The motor operates the link chain 33 through the reduction gearing 45 and moves the pin I04 until the end thereof strikes against the cross bar 91 which thereby moves the ejector and the shovel 25 along therewith. This movement continues until the detent 81 on the underside of the latch 83 strikes the stop block 36, at which point the engaging projection 85 on the latch moves from the slot 86 thereof and the shovel ceases its forward movement while the ejector continues to advance. The forward movement of the shovel raises the door I01 and the arm 2| as illustrated in Fig. 8. The inner door 61 rotates counterclockwise when the projecting arm 69 thereof moves overthe lip 1| of the nose 24 into the position illustrated-in Fig.v 8. *A further movement of the door scatters the fuel in the fire box to prepare a surface for the fuel which is ad vanced through the shovel by the ejector 65. The ejector completes its forward movement asthe pin I04 is carried around the sprocket 49 of the driving mechanism.

By adjusting the position of the block 36. and

the cross bar 91, the degree, of movement of the gaging portion 85 into the aperture 86 for locking the ejector and shovel together for combined forward movement. The rearward operation continues until the pin I04 approaches its rearmost position, that illustrated in Fig. 6, whereupon the cam element 55 on the side of the I shovel contacts the cam I06 to tilt the switch 22 in the opposite direction, whereupon the circuit to the motor 23 is broken and the ejector operation is completed with the arm 2| in raised position resting upon the fuel which has been injected into the furnace. Through the lowering of the arm as the fuel burns, additional fuel is periodically injected into the fire box. By mounting the stoker on wheels, it may be readily moved from its position against the furnace so that the accumulated ashes and clinkers maybe removed, after which the stoker may be moved into its original firing position.

While I have described and illustrated but a but a single embodiment of my invention, it will be apparent to those skilled in the art that various changes, omissions, additions and substitutions may be made therein without departing from the spirit and scope of my invention, as set forth in the accompanying claims.

I claim as my invention:

1. A stoker embodying a base, a support on said base, a hopper on said support, a shovel slidable in said support, an ejector slidable within said shovel, a link chain mounted within said support, means for driving said chain, a crank arm attached to said chain slidably supported on said ejector, an adjustable element on said ejector engageable by said crank arm, and a latch on said shovel engaging said ejector.

2. A stoker embodying a base, a support on said base, a hopper on said support, a shovel slidable in said support, an ejector slidable within said shovel, a link chain mounted within said support, means for driving said chain, a crank arm attached to said chain slidably supported on said ejector, an adjustable element on said ejector engageable by said crank arm, a latch on said shovel engaging said ejector, and an adjustable element on said support in the path of movement of said latch for releasing the shovel from said ejector as the ejector is moved by said crank arm.

3. A stoker embodying a base, a support on said base, a hopper on said support, a shovel slidable in said support, an ejector slidable within said shovel, a link chain mounted within said support, means for driving said chain, a crank arm attached to said chain slidably supported on said ejector, an adjustable element on said 75 ejector engageable, by said crank arm, a latch on said shovel engaging said ejector, an adjustable element on said support in the path of movement of said latch for releasing the shovel from saidejector as the ejector is moved by said crank arm, an additional detent on said latch for locking said shovel against reverse movement, and a projection on said latch engageable by said ejector upon its return movement for releasing and carrying the shovel therewith and for engaging the latch with the ejector for forward movement.

4. In combination with a movable shovel of a stoker having sides and a bottom web, of a door pivoted near the end of said shovel on the bottom web thereof, said door having spaced walls forming a hollow construction to prevent the inner surface of the door from being excessively heated.

5. In a stoker, the combination with a slidable shovel, a door pivoted near the end of said shovel, said door having a plate on the underside thereof to provide thickness, and a frontal face which is available to scatter the burning coal within the fire box of a furnace as the shovel is advanced.

6. In a stoker, the combination with a slidable shovel, a door pivoted on said shovel, a support for said shovel, an arm projecting from said door operated by the end of said support, to permit the door to move to open position and to positively-close said door.

7. In a stoker the combination with a support and a hopper mounted thereon, a shovel movable forwardly in said support beneath said hopper, and a flange projecting over the edge of said shovel and projecting thereinto beneath said hopper and forwardly thereof.

8. In a stoker the combination with a support and a hopper mounted thereon, a shovel movable forwardly in said support beneath said hopper, a flange projecting over the edge of said shovel and projecting thereinto beneath said hopper and forwardly thereof, and a bafile projecting into said shovel forwardly of said hopper.

9. A stoker including in combination a support having a hopper mounted thereon, a shovel having upstanding sides carried by said support and movable forwardly beneath the sides of said hopper, said shovel having a pair of bottom webs in spaced relation, an ejector movable between said webs, a seal between said upper web and a wall of the hopper which projects into said shovel, and a seal between the lower web and the ejector.

10. A stoker including in combination a support having a hopper mounted thereon, a shovel having upstanding sides carried by said support and movable forwardly beneath the sides of said hopper, said shovel having a pairof bottom webs in spaced relation, an ejector movable between said webs, a seal between said upper web and a wall of the hopper which projects into said shovel, a seal between the lower web and the ejector, driving means for moving said ejector and shovel forwardly as a unit, and means for terminating the advancement of the shovel as the ejector continues its forward movement.

11. A stoker including in combination a support having a hopper mounted thereon, a shovel having upstanding sides carried by said support and movable forwardly beneath the sides of said hopper, said shovel having a pair of bottom webs in spaced relation, an ejector movable between said webs, a seal between said upper web and a wall of the hopper which projects into said shovel, a seal between the lower web and the ejector, driving means for moving said ejector and shovel forwardly as a unit, means for terminating the advancement of the shovel as the ejector continues its forward movement, and means for locking said shovel against rearward movement during a portion of the return movement of the ejector.

12. In a stoker, the combination with a base having a hopper supported thereabove, a slidable shovel below said hopper for receiving the fuel thereof, and a baffle projecting into said 5 shovel at the forward edge of said hopper for controlling the flow of fuel within the shovel, and a door on the front end of the stoker forwardly of said shovel and baffle.

FREDERICK W. VODOZ. 

